Bearer handover control device and control method

ABSTRACT

Embodiments of the present invention disclose a bearer handover control device and control method. The method includes: receiving, by a network side device, a bearer handover message; and determining, by the network side device according to the bearer handover message, a bearer needing to be handed over in all bearers, so that an end marker End Marker message is sent to a source base station only for the bearer needing to be handed over. By using the foregoing solutions, for a multi-connection scenario, a network side device can determine a bearer needing to be handed over, so that an end marker message is sent only for the bearer needing to be handed over, which can prevent discarding of subsequent data of a bearer that is not to be handed over, and ensure multiple connections between a UE and base stations, thereby improving stability of a system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2014/079769 filed on Jun. 12, 2014, the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments of the present invention relate to the communications field,and in particular, to a bearer handover control device and controlmethod.

BACKGROUND

A wireless network architecture of a current evolved packet system (EPS)is shown in FIG. 1, in which functions of main network entities are asfollows:

An evolved universal terrestrial radio access network (E-UTRAN) is anetwork including a plurality of base stations (Evolved Node B, eNodeB,or eNB), and implements a wireless physical layer function, andfunctions of resource scheduling and wireless resource management,wireless access control, and mobility management. An eNodeB is connectedto an S-GW by using a user plane interface S1-U, to transfer user data,and is connected to an MME by using a control plane interface S1-MME, toimplement functions, such as radio access bearer control, by using theS1-AP protocol.

The mobility management entity (MME) is mainly responsible for allcontrol plane functions of user session management, which includenon-access-stratum (NAS) signaling and security management, trackingarea list management, selection of a P-GW and an S-GW, and the like.

The serving gateway (S-GW or SGW) is mainly responsible for datatransmission, data forwarding, and route switching of user equipment(UE), and serves as a local mobility anchor point when the userequipment is handed over between eNodeBs. For each user equipment, onlyone S-GW serves the user equipment at each moment.

A PDN gateway P-GW, or PGW) serves as an anchor point for connecting toa packet data network (PDN), and is responsible for allocation of an IPaddress to the user equipment, filtration of a data packet for the userequipment, rate control, charging information generation, and the like.

The user equipment accesses the EPS network and establishes a PDNconnection by using an attach procedure. In this process, the PGWallocates a PDN address to the user equipment, and the user equipment isconnected to the PGW by using the PDN address and implements datatransmission with an external network by using the PGW. After the attachprocedure ends, the UE may apply for an extra PDN connection to obtainan extra PDN address, and a specific procedure is similar to the attachprocedure.

In order to solve a bottleneck problem in air interface transmission, itis expected by people that a dual connectivity feature can be used bythe UE, so as to increase a rate of transmission between the UE and abase station. That is, the UE is connected to two eNBs at the same time,and a plurality of bearers is transmitted on the different eNBs.However, in a conventional bearer process, there is no special controlon dual connectivity. When a first eNB transfers some bearers of the UEto a second eNB, because a corresponding network side device does notknow a dual connectivity process thereof, a conventional manner forprocessing a single-connection bearer is still used. Obviously, such amanner for processing a single connection cannot satisfy adual-connectivity processing requirement when it is applied todual-connectivity bearers, thereby leading to communication abnormality.

SUMMARY

In view of this, embodiments of the present invention provide a bearerhandover control device and control method, which can solve a problem ofa bearer loss in a multi-connection scenario.

An embodiment of the present invention provides a network side device,configured to control a bearer handover, where the network side devicebelongs to a wireless communications system, where the system furtherincludes a source base station and a target base station, and at leastsome of all bearers between user equipment and the source base stationneed to be handed over from the source base station to the target basestation, and the network side device includes: a receiving unit,configured to receive a bearer handover message; and a processing unit,configured to determine, according to the bearer handover message, abearer needing to be handed over in all the bearers, so that an endmarker End Marker message is sent to the source base station only forthe bearer needing to be handed over.

Optionally, the network side device is a serving gateway SGW, where thereceiving unit configured to receive a bearer handover message includes:a receiving unit of the SGW, configured to receive at least one bearermodification request message sent by a mobility management entity MME,where bearer contexts included in the at least one bearer modificationrequest message correspond to all the bearers; the processing unitconfigured to determine, according to the bearer handover message, abearer needing to be handed over in all the bearers, so that an endmarker End Marker message is sent to the source base station only forthe bearer needing to be handed over includes: a processing unit of theSGW, configured to determine, according to the bearer contexts in the atleast one bearer modification request message, the bearer needing to behanded over; and the SGW further includes a sending unit, configured tosend the End Marker message to the source base station only for thebearer needing to be handed over.

Optionally, the processing unit of the SGW configured to determine,according to the bearer contexts in the at least one bearer modificationrequest message, the bearer needing to be handed over includes: beingconfigured to match fully qualified tunnel endpoint identifiers (FullyQualified Tunnel End Point Identifier, F-TEID) in the bearer contexts inthe at least one bearer modification request message with F-TEIDs inbearer contexts that are currently stored by the SGW, and when an F-TEIDof a bearer is changed, determine that the bearer is a bearer needing tobe handed over; or being configured to match base station addresses inthe bearer contexts in the at least one bearer modification requestmessage with base station addresses in bearer contexts that arecurrently stored by the SGW, and when a base station address of a beareris changed, determine that the bearer is a bearer needing to be handedover.

Optionally, the network side device is a serving gateway SGW, where thereceiving unit configured to receive a bearer handover message includes:a receiving unit of the SGW, configured to receive at least one bearermodification request message sent by a mobility management entity MME,where the bearer modification request message includes first indicationinformation, and the first indication information indicates the bearerneeding to be handed over; the processing unit configured to determine,according to the bearer handover message, a bearer needing to be handedover in all the bearers, so that an end marker End Marker message issent to the source base station only for the bearer needing to be handedover includes: a processing unit of the SGW, configured to determine,according to the first indication information in the at least one bearermodification request message, the bearer needing to be handed over; andthe SGW further includes a sending unit, configured to send the EndMarker message to the source base station only for the bearer needing tobe handed over.

Optionally, each bearer modification request message of the at least onebearer modification request message includes one piece of firstindication information, where the first indication information indicatesthat all bearers in the bearer modification request are bearers needingto be handed over; or each bearer modification request message of the atleast one bearer modification request message includes a plurality ofpieces of first indication information, where each bearer in the bearermodification request corresponds to one piece of first indicationinformation, and each piece of indication information indicates whethera corresponding bearer needs to be handed over.

Optionally, the processing unit of the SGW is further configured toreserve a context of a bearer that does not need to be handed over.

Optionally, the network side device is a mobility management entity MME,where the receiving unit configured to receive a bearer handover messageincludes: a receiving unit of the MME, configured to receive an evolveduniversal terrestrial radio access network radio access bearer E-RABmodification indication message sent by the source base station, wherebearer contexts included in the E-RAB modification indication messagecorrespond to all the bearers; the processing unit configured todetermine, according to the bearer handover message, a bearer needing tobe handed over in all the bearers, so that an end marker End Markermessage is sent to the source base station only for the bearer needingto be handed over includes: a processing unit of the MME, configured todetermine, according to the bearer contexts in the E-RAB modificationindication message, the bearer needing to be handed over; and the MMEfurther includes a sending unit, configured to send a bearermodification request message to an SGW, where a bearer context carriedin the bearer modification request message includes only a bearercontext of the bearer needing to be handed over.

Optionally, the processing unit of the MME configured to determine,according to the bearer contexts in the E-RAB modification indicationmessage, the bearer needing to be handed over includes: being configuredto match F-TEIDs in bearer contexts of all bearers in the E-RABmodification indication message with F-TEIDs of currently stored bearercontexts, and when an F-TEID of a bearer is changed, determine that thebearer is a bearer needing to be handed over; or being configured tomatch base station addresses in bearer contexts of all bearers in theE-RAB modification indication message with base station addresses inbearer contexts that are currently stored by the MME, and when a basestation address of a bearer is changed, determine that the bearer is abearer needing to be handed over.

Optionally, the network side device is a mobility management entity MME,where the receiving unit configured to receive a bearer handover messageincludes: a receiving unit of the MME, configured to receive an E-RABmodification indication message sent by the source base station, wherethe E-RAB modification indication message includes second indicationinformation, and the second indication information indicates the bearerneeding to be handed over; the processing unit configured to determine,according to the bearer handover message, a bearer needing to be handedover in all the bearers, so that an end marker End Marker message issent to the source base station only for the bearer needing to be handedover includes: a processing unit of the MME, configured to determine,according to the second indication information in the E-RAB modificationindication message, the bearer needing to be handed over; and the MMEfurther includes a sending unit, configured to send at least one bearermodification request message to an SGW, where a bearer context carriedin the at least one bearer modification request message includes only acontext of the bearer needing to be handed over; or the at least onebearer modification request message includes first indicationinformation, and the first indication information indicates the bearerneeding to be handed over.

Optionally, the E-RAB modification indication message includes one pieceof second indication information, where the second indicationinformation indicates all bearers in the E-RAB modification indicationmessage are bearers needing to be handed over; or the E-RAB modificationindication message includes a plurality of pieces of second indicationinformation, where each bearer in the E-RAB modification indicationmessage corresponds to one piece of second indication information, andeach piece of indication information indicates whether a correspondingbearer needs to handed over.

Optionally, each bearer modification request message of the at least onebearer modification request message includes one piece of firstindication information, where the first indication information indicatesthat all bearers in the bearer modification request are bearers needingto be handed over; or each bearer modification request message of the atleast one bearer modification request message includes a plurality ofpieces of first indication information, where each bearer in the bearermodification request corresponds to one piece of first indicationinformation, and each piece of indication information indicates whethera corresponding bearer needs to be handed over.

An embodiment of the present invention provides a bearer handovercontrol method. The method is applicable to a wireless communicationssystem, where the system includes a network side device, a source basestation, and a target base station, and at least some of all bearersbetween user equipment and the source base station need to be handedover from the source base station to the target base station, and themethod includes following steps: receiving, by the network side device,a bearer handover message; and determining, by the network side deviceaccording to the bearer handover message, a bearer needing to be handedover in all the bearers, so that an end marker End Marker message issent to the source base station only for the bearer needing to be handedover.

Optionally, the network side device is a serving gateway SGW, where thereceiving, by the network side device, a bearer handover messageincludes: receiving, by the SGW, at least one bearer modificationrequest message sent by a mobility management entity MME, where bearercontexts included in the at least one bearer modification requestmessage correspond to all the bearers; and the determining, by thenetwork side device according to the bearer handover message, a bearerneeding to be handed over in all the bearers, so that an end marker EndMarker message is sent to the source base station only for the bearerneeding to be handed over includes: determining, by the SGW according tothe bearer contexts in the at least one bearer modification requestmessage, the bearer needing to be handed over; and sending, by the SGW,the End Marker message to the source base station only for the bearerneeding to be handed over.

Optionally, the determining, by the SGW according to the bearer contextsin the at least one bearer modification request message, the bearerneeding to be handed over includes: matching, by the SGW, F-TEIDs in thebearer contexts in the at least one bearer modification request messagewith F-TEIDs in bearer contexts that are currently stored by the SGW,and when an F-TEID of a bearer is changed, determining that the beareris a bearer needing to be handed over; or matching, by the SGW, basestation addresses in the bearer contexts in the at least one bearermodification request message with base station addresses in bearercontexts that are currently stored by the SGW, and when a base stationaddress of a bearer is changed, determining that the bearer is a bearerneeding to be handed over.

Optionally, the network side device is a serving gateway SGW, where thereceiving, by the network side device, a bearer handover messageincludes: receiving, by the SGW, at least one bearer modificationrequest message sent by a mobility management entity MME, where thebearer modification request message includes first indicationinformation, and the first indication information indicates the bearerneeding to be handed over; and the determining, by the network sidedevice according to the bearer handover message, a bearer needing to behanded over in all the bearers, so that an end marker End Marker messageis sent to the source base station only for the bearer needing to behanded over includes: determining, by the SGW according to the firstindication information in the at least one bearer modification requestmessage, the bearer needing to be handed over; and sending, by the SGW,the End Marker message to the source base station only for the bearerneeding to be handed over.

Optionally, each bearer modification request message of the at least onebearer modification request message includes one piece of firstindication information, where the first indication information indicatesthat all bearers in the bearer modification request are bearers needingto be handed over; or each bearer modification request message of the atleast one bearer modification request message includes a plurality ofpieces of first indication information, where each bearer in the bearermodification request corresponds to one piece of first indicationinformation, and each piece of first indication information indicateswhether a corresponding bearer needs to be handed over.

Optionally, the control method further includes: reserving, by the SGW,a context of a bearer that does not need to be handed over.

Optionally, the network side device is a mobility management entity MME,where the receiving, by the network side device, a bearer handovermessage includes: receiving, by the MME, an evolved universalterrestrial radio access network radio access bearer E-RAB modificationindication message sent by the source base station, where bearercontexts included in the E-RAB modification indication messagecorrespond to all the bearers; and the determining, by the network sidedevice according to the bearer handover message, a bearer needing to behanded over in all the bearers, so that an end marker End Marker messageis sent to the source base station only for the bearer needing to behanded over includes: determining, by the MME according to the bearercontexts in the E-RAB modification indication message, the bearerneeding to be handed over; and sending, by the MME, a bearermodification request message to an SGW, where a bearer context carriedin the bearer modification request message includes only a context ofthe bearer needing to be handed over.

Optionally, the determining, by the MME according to the bearer contextsin the E-RAB modification indication message, the bearer needing to behanded over includes: matching, by the MME, F-TEIDs in bearer contextsof all bearers in the E-RAB modification indication message with F-TEIDsof currently stored bearer contexts, and when an F-TEID of a bearer ischanged, determining that the bearer is a bearer needing to be handedover; or matching, by the MME, target base station addresses in bearercontexts of all bearers in the E-RAB modification indication messagewith base station addresses in bearer contexts that are currently storedby the MME, and when a base station address of a bearer is changed,determining that the bearer is a bearer needing to be handed over.

Optionally, the network side device is a mobility management entity MME,where the receiving, by the network side device, a bearer handovermessage includes: receiving, by the MME, an E-RAB modificationindication message sent by the source base station, where the E-RABmodification indication message includes second indication information,and the second indication information indicates the bearer needing to behanded over; and the determining, by the network side device accordingto the bearer handover message, a bearer needing to be handed over inall the bearers, so that an end marker End Marker message is sent to thesource base station only for the bearer needing to be handed overincludes: determining, by the MME according to the second indicationinformation in the E-RAB modification indication message, the bearerneeding to be handed over; and sending, by the MME, at least one bearermodification request message to an SGW, where a bearer context carriedin the at least one bearer modification request message includes only acontext of the bearer needing to be handed over; or the at least onebearer modification request message includes first indicationinformation, and the first indication information indicates the bearerneeding to be handed over.

Optionally, the E-RAB modification indication message includes one pieceof second indication information, where the indication informationindicates all bearers in the E-RAB modification indication message arebearers needing to be handed over; or the E-RAB modification indicationmessage includes a plurality of pieces of second indication information,where each bearer in the E-RAB modification indication messagecorresponds to one piece of second indication information, and eachpiece of indication information indicates whether a corresponding bearerneeds to handed over.

Optionally, each bearer modification request message of the bearermodification request message includes one piece of first indicationinformation, where the first indication information indicates that allbearers in the bearer modification request are bearers needing to behanded over; or each bearer modification request message of the at leastone bearer modification request message includes a plurality of piecesof first indication information, where each bearer in the bearermodification request corresponds to one piece of first indicationinformation, and each piece of first indication information indicateswhether a corresponding bearer needs to be handed over.

By using the foregoing solutions, for a multi-connection scenario, anetwork side device can determine a bearer needing to be handed over, sothat an end marker message is sent only for the bearer needing to behanded over, which can prevent discarding of subsequent data of a bearerthat is not to be handed over, and ensure multiple connections between aUE and base stations, thereby improving stability of a system.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments of thepresent invention. Apparently, the accompanying drawings in thefollowing description show merely some embodiments of the presentinvention, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a schematic diagram of a wireless network architecture in theprior art;

FIG. 2 is a schematic diagram in which a UE establishes a bearer byusing an attach procedure;

FIG. 3 is a schematic diagram of a single-connection bearer handover;

FIG. 4 is a block diagram of a network side device according toEmbodiment 1 of the present invention;

FIG. 5 is a schematic diagram of a technical solution for controlling abearer handover according to Embodiment 2 of the present invention;

FIG. 6 is a block diagram of an SGW according to Embodiment 2 of thepresent invention;

FIG. 7 is a schematic diagram of a technical solution for controlling abearer handover according to Embodiment 3 of the present invention;

FIG. 8 is a block diagram of an MME according to Embodiment 3 of thepresent invention;

FIG. 9 is a schematic diagram of a bearer handover control methodaccording to Embodiment 4 of the present invention;

FIG. 10 is a schematic diagram of a bearer handover control methodaccording to Embodiment 5 of the present invention;

FIG. 11 is a schematic diagram of a bearer handover control methodaccording to Embodiment 6 of the present invention;

FIG. 12 is a block diagram of a network side device according toEmbodiment 9 of the present invention;

FIG. 13 is a block diagram of an SGW according to Embodiment 10 of thepresent invention; and

FIG. 14 is a block diagram of an MME according to Embodiment 11 of thepresent invention.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are some but not all of the embodiments of thepresent invention. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentinvention without creative efforts shall fall within the protectionscope of the present invention.

A base station mentioned in the present invention may be a base stationin a Long Term Evolution (LTE) system, may also be a base station in aUniversal Mobile Telecommunications System (UMTS), and may also be abase station in another system, which is not limited in the presentinvention.

FIG. 2 shows a communications system, and the communications systemincludes entities such as a source base station, a target base station,and user equipment. A process of establishing a bearer by the userequipment by using a conventional attach procedure is briefly describedherein with reference to FIG. 2. Description is merely exemplary herein,and some entities, for example, a home subscriber server (HSS) entity,and related processing are omitted. Numbers of the following steps donot limit the order of the steps.

Step 201: The UE sends an attach request to an MME through an eNB.

Step 202: The MME selects a corresponding SGW and PGW, and sends asession creation request to the SGW.

Step 203: The SGW creates information about a default bearer context,and sends the session creation request to the PGW.

Step 204: The PGW creates information about a default bearer context,and sends a session creation response message to the SGW.

Step 205: The SGW returns a session creation response to the MME.

Step 206: The MME sends an attach accept message to the eNB.

Step 207: The eNB and the UE complete the attach procedure by using anRRC connection reconfiguration message.

Correspondingly, entities passed through by the foregoing bearer maycorrespondingly store a bearer context and related information, andrecord the bearer context and the related information in memories of thecorresponding entities. After the bearer is successfully established,the UE establishes at least one bearer with the PGW. The SGW storesbearer contexts of all bearers corresponding to the UE. Specifically,one PDN connection exists between one UE and one PGW; and one UE mayestablish a plurality of PDN connections with a plurality of PGWs.

As shown in FIG. 3, a communications system includes a source basestation, a target base station, and user equipment, where at least someof all bearers between the user equipment and the source base stationneed to be handed over from the source base station to the target basestation. If existing processing for a single connection is performed ina process of completing dual connectivity by using an E-RAB modificationprocedure, the implementation process may be as follows:

Step 301: A first eNB (a Master eNB in FIG. 3) initiates a second eNBmodification procedure, and transmits, to a second eNB, a bearer contextof a bearer needing to be handed over to the second eNB, where thebearer context includes information such as a bearer identifier, QoS, anSGW address of uplink data, and a TEID.

Step 302: The first eNodeB sends an E-RAB modification indicationmessage to an MME, where the message carries bearer contexts of allbearers of the user equipment, which include an eNB address and TEIDinformation that correspond to each bearer, the bearer context of thebearer needing to be handed over to the second eNB carries an addressand a TEID of the second eNB, and a bearer context of a bearer that doesnot need to be handed over carries an original eNB address and TEID.

Step 303: The MME sends a bearer modification request message to an SGW,where the message carries a bearer context, and the bearer contextincludes an eNB address and TEID information that correspond to abearer.

Step 304: The SGW returns a bearer modification response message to theMME.

Step 305: The MME sends an E-RAB modification acknowledgment message tothe first eNB.

Step 306: After step 303, the SGW sends, on an old path, End markermessages to the first eNB for all the bearers, and at the same time, theSGW updates, according to the bearer modification request message, eNBaddresses and TEIDs that correspond to all the bearers; after receivingthe End marker messages, the first eNB forwards the correspondingbearers to the second eNB. The first eNB forwards the End markers forthe bearers to the second eNB. Because these End marker messagescorrespond to all the bearers, after receiving the End Markers, thefirst eNB stops receiving all subsequent packets corresponding to allthe bearers. As a result, the first eNB discards subsequent downlinkdata of a bearer that is not to be handed over, which leads tointerruption of a user service, and the second eNB does not expect toaccept the bearer that does not need to be handed over, thereby causinga service contradiction.

Based on a problem of a data loss that may exist in the foregoingsolution, the embodiments of the present invention provide correspondingimplementation solutions for controlling a bearer handover. Theseimplementation solutions are described in detail below.

Embodiment 1

As shown in FIG. 4, this embodiment of the present invention provides anetwork side device, configured to control a bearer handover. Thenetwork side device belongs to a wireless communications system, wherethe system further includes a source base station and a target basestation, and at least some of all bearers between user equipment and thesource base station need to be handed over from the source base stationto the target base station, and the network side device 400 includes:

a receiving unit 403, configured to receive a bearer handover message;and

a processing unit 401, configured to determine, according to the bearerhandover message, a bearer needing to be handed over in all the bearers,so that an end marker End Marker message is sent to the source basestation only for the bearer needing to be handed over.

By using the foregoing solution, for a multi-connection scenario, anetwork side device can determine a bearer needing to be handed over, sothat an end marker message is sent only for the bearer needing to behanded over, which can prevent discarding of subsequent data of a bearerthat is not to be handed over, and ensure multiple connections between aUE and base stations, thereby improving stability of a system.

The network side device in this embodiment may be a serving gateway SGW,and may also be a mobility management entity MME, which is describedspecifically below.

Embodiment 2

A technical solution in which a network side device is an SGW isdescribed in this embodiment.

This embodiment provides a technical solution, where a UE keeps incommunication with a source base station, and the source base stationprepares, according to conditions of bearers, to hand over some of thebearers to a target base station. Specifically, as shown in FIG. 5, thesolution may include the following steps:

Step 501: The source base station may determine, by using a parametersuch as Qos of the UE or the source base station or a load conditionbetween the UE and the source base station, a bearer needing to behanded over.

There are one or more bearers needing to be handed over.

Step 502: The source base station sends an E-RAB modification indicationmessage to an MME, where bearer contexts included in the E-RABmodification indication message correspond to all the bearers; the MMEsends at least one bearer modification request message to the SGWaccording to the E-RAB modification indication message, where bearercontexts included in the at least one bearer modification requestmessage correspond to all the bearers.

The at least one bearer modification request message sent by the MME mayinclude a plurality of bearer modification request messages. Each bearermodification request message corresponds to one PDN connection, a bearercorresponding to a context included in each bearer modification requestmessage corresponds to the PDN connection corresponding to the bearermodification request message, and the contexts included in all thebearer modification request messages correspond to all the bearers.

Step 503: The SGW may receive the at least one bearer modificationrequest message sent by the mobility management entity MME, where thebearer contexts included in the at least one bearer modification requestmessage correspond to all the bearers; the SGW may determine, accordingto the bearer contexts in the at least one bearer modification requestmessage, the bearer needing to be handed over.

Subsequently, the SGW may send a bearer modification response message tothe MME, and the MME may send an E-RAB modification acknowledgmentmessage to the source base station, and details are not describedherein.

Step 504: The SGW may send an End Marker message to the source basestation only for the bearer needing to be handed over.

Step 505: After receiving the End Marker message, the source basestation may forward the received End Marker message to the target basestation.

The End Marker message received by the source base station correspondsonly to the bearer needing to be handed over, and does not include abearer that does not need to be handed over. Correspondingly, the sourcebase station reserves the bearer that does not need to be handed over,and stops a subsequent packet of the bearer needing to be handed over.The source base station transfers, to the target base station, thebearer needing to be handed over. The source base station may alsoforward the received End Marker message to the target base station;after receiving the message, the target base station may confirm thatthe source base station has completed sending a data stream of thebearer needing to be handed over, and start communication between thetarget base station and the corresponding UE and network side device.

Correspondingly, as shown in FIG. 6, the SGW 600 may include: areceiving unit 603, configured to receive the at least one bearermodification request message sent by the mobility management entity MME,where the bearer contexts included in the at least one bearermodification request message correspond to all the bearers;

a processing unit 601, configured to determine, according to the bearercontexts in the at least one bearer modification request message, thebearer needing to be handed over; and

a sending unit 602, configured to send the End Marker message to thesource base station only for the bearer needing to be handed over.

The sending the End Marker message only for the bearer needing to behanded over refers to that the End Marker message is sent for the bearerneeding to be handed over, and the End Marker message is not sent forthe bearer that does not need to be handed over.

The bearer refers to a transmission channel between user equipment and aPGW. The transmission channel includes entities such as the userequipment, a base station, an MME, an SGW, and the PGW. When the SGWsends the End Marker message, in order to prevent a loss of an EndMarker, at least one End Marker may be sent for each bearer.

By using the foregoing solution, for a multi-connection scenario, an SGWcan determine a bearer needing to be handed over, so that the SGW sendsan end marker message only for the bearer needing to be handed over,which can prevent discarding of subsequent data of a bearer that is notto be handed over, and ensure multiple connections between a UE and basestations, thereby improving stability of a system.

Further, the bearer contexts included in the at least one bearermodification request message include F-TEIDs. Each bearer contextcorresponds to one F-TEID. The SGW matches the F-TEIDs of the receivedbearer contexts with F-TEIDs in corresponding bearer contexts that areobtained by the SGW during bear establishment. When an F-TEID of abearer is changed, it is determined that the bearer is a bearer needingto be handed over. Generally, the SGW may obtain corresponding bearercontexts during bearer establishment, and store the corresponding bearercontexts in a memory of the SGW. The F-TEIDs generally include basestation addresses and TEID information. The SGW may also obtain, bymatching only the base station addresses, the bearer needing to behanded over. The SGW may also obtain, by matching the base stationaddresses and TEID information, the bearer needing to be handed over.

Correspondingly, the processing unit of the SGW configured to determine,according to the bearer contexts in the at least one bearer modificationrequest message, the bearer needing to be handed over includes: beingconfigured to match the F-TEIDs in the bearer contexts in the at leastone bearer modification request message with F-TEIDs in bearer contextsthat are currently stored by the SGW, and when an F-TEID of a bearer ischanged, determine that the bearer is a bearer needing to be handedover; or

being configured to match the base station addresses in the bearercontexts in the at least one bearer modification request message withbase station addresses in bearer contexts that are currently stored bythe SGW, and when a base station address of a bearer is changed,determine that the bearer is a bearer needing to be handed over.

Further, the processing unit of the SGW is further configured to reservea context of the bearer that does not need to be handed over. In thisway, the SGW can keep normal communication of an original bearer.

In the foregoing solution, a bearer needing to be handed over can bedetermined by matchingF-TEIDs or base station addresses; therefore,subsequently, a corresponding End Marker is sent only for the bearerneeding to be handed over. In the solution, new signaling does not needto be added additionally, thereby saving a signaling resource.

As another possible implementation manner, the SGW can obtain the bearerneeding to be handed over, without matching the F-TEIDs or the basestation addresses. The SGW may indicate, by using indicationinformation, the bearer needing to be handed over. Specifically, theE-RAB modification indication message sent by the source base station tothe MME includes second indication information, and the secondindication information indicates the bearer needing to be handed over.The MME generates, according to the E-RAB modification indicationmessage and the corresponding second indication information, at leastone bearer modification request message, where the bearer modificationrequest message includes first indication information, and the firstindication information indicates the bearer needing to be handed over;the MME sends the at least one bearer modification request message tothe SGW. The SGW may receive the at least one bearer modificationrequest message sent by the mobility management entity MME, where thebearer modification request message includes the first indicationinformation, and the first indication information indicates the bearerneeding to be handed over; determine, according to the first indicationinformation in the at least one bearer modification request message, thebearer needing to be handed over; and send the End Marker message to thesource base station only for the bearer needing to be handed over. Aprocess between the source base station and the target base station isconsistent with the foregoing solution for performing matching on theF-TEIDs or the base station addresses, and details are not describedagain.

Correspondingly, the receiving unit configured to receive a bearerhandover message includes: a receiving unit, configured to receive theat least one bearer modification request message sent by the mobilitymanagement entity MME, where the bearer modification request messageincludes the first indication information, and the first indicationinformation indicates the bearer needing to be handed over;

the processing unit is configured to determine, according to the firstindication information in the at least one bearer modification requestmessage, the bearer needing to be handed over; and

the sending unit is configured to send the End Marker message to thesource base station only for the bearer needing to be handed over.

First indication information is added to a bearer modification requestmessage to determine a bearer needing to be handed over, so that an SGWdoes not need to perform an additional matching action, thereby saving acomputing resource.

In addition, different granularities may be used for the firstindication information that is in the bearer modification requestmessage and that the MME notifies to the SGW, which includes that: onebearer modification request message includes one piece of firstindication information, where the first indication information indicatesthat all bearers in the bearer modification request are bearers needingto be handed over; or each bearer modification request message of the atleast one bearer modification request message includes a plurality ofpieces of first indication information, where each bearer in the bearermodification request corresponds to one piece of first indicationinformation, and each piece of indication information indicates whethera corresponding bearer needs to be handed over. The bearer needing to behanded over can be indicated by both of the foregoing two solutions. Inthe first solution, one piece of indication information is used toindicate a plurality of bearers, which can save signaling. By using thesecond solution, whether each bearer needs to be handed over can beaccurately indicated, so that an indication is more accurate.

Further, the processing unit of the SGW is further configured to reservea context of a bearer that does not need to be handed over. In this way,the SGW can keep normal communication of an original bearer.

Embodiment 3

A technical solution in which a network side device is an MME isdescribed in this embodiment.

Similar to the solution in FIG. 5, this embodiment provides a technicalsolution. Specifically, the solution may include the following steps:

Step 701: A source base station determines a bearer needing to be handedover, and sends an E-RAB modification indication message to an MME,where bearer contexts included in the E-RAB modification indicationmessage correspond to all bearers.

Step 702: The MME determines, according to the bearer contexts in theE-RAB modification indication message, the bearer needing to be handedover.

Step 703: The MME sends a bearer modification request message to an SGW,where a bearer context carried in the bearer modification requestmessage includes only a context of the bearer needing to be handed over.

Step 704: The SGW sends, according to the bearer context carried in thereceived bearer modification request message, an End Marker message tothe source base station only for the bearer needing to be handed over.

A subsequent process between the source base station and a target basestation is consistent with the solution in FIG. 5, and details are notdescribed again.

It should be noted that in this embodiment, the MME needs to storebearer contexts of all the bearers after bearer establishment.Correspondingly, the SGW does not delete a context of a bearer that isnot included in the bearer modification request message from the MME,and reserves the bearer as a bearer that does not need to be handedover.

Correspondingly, as shown in FIG. 8, the MME 800 may include:

a receiving unit 803, configured to receive the E-RAB modificationindication message sent by the source base station, where the bearercontexts included in the E-RAB modification indication messagecorrespond to all the bearers; and

a processing unit 801, configured to determine, according to the bearercontexts in the E-RAB modification indication message, the bearerneeding to be handed over; and

a sending unit 802, configured to send the bearer modification requestmessage to the SGW, where the bearer context carried in the bearermodification request message includes only the bearer context of thebearer needing to be handed over.

Correspondingly, a receiving unit of the SGW is configured to receivethe bearer modification request message, where the bearer modificationrequest message indicates the bearer needing to be handed over and thecontext of the bearer needing to be handed over;

a processing unit of the SGW is configured to generate the End Markermessage according to the bearer modification request message for thebearer needing to be handed over; and

a sending unit of the SGW sends the End Marker message for the bearerneeding to be handed over.

Further, the processing unit of the SGW is further configured to reservethe context of the bearer that does not need to be handed over.

By using the foregoing solution, for a multi-connection scenario, an MMEcan determine a bearer needing to be handed over, so that an SGW cansend an end marker message only for the bearer needing to be handedover, which can prevent discarding of subsequent data of a bearer thatis not to be handed over, and ensure multiple connections between a UEand base stations, thereby improving stability of a system.

Further, the bearer contexts included in the E-RAB modificationindication message include F-TEIDs. The MME matches the F-TEIDs of thereceived bearer contexts with F-TEIDs in corresponding bearer contextsthat are obtained by the MME during bear establishment. When an F-TEIDof a bearer is changed, it is determined that the bearer is a bearerneeding to be handed over. Generally, the MME may obtain correspondingbearer contexts during bearer establishment, and store the correspondingbearer contexts in a memory of the MME. Similar to Embodiment 2, the MMEmay also obtain, by matching only changes of base station addresses, thebearer needing to be handed over. The MME may also obtain, by matchingthe base station addresses and TED information, the bearer needing to behanded over.

Correspondingly, the processing unit of the MME configured to determine,according to the bearer contexts in the E-RAB modification indicationmessage, the bearer needing to be handed over includes: being configuredto match the F-TEIDs in the bearer contexts of all the bearers in theE-RAB modification indication message with F-TEIDs in currently storedbearer contexts, and when an F-TEID of a bearer is changed, determinethat the bearer is a bearer needing to be handed over; or

being configured to match base station addresses in the bearer contextsof all the bearers in the E-RAB modification indication message withbase station addresses in bearer contexts that are currently stored bythe MME, and when a base station address of a bearer is changed,determine that the bearer is a bearer needing to be handed over.

A bearer needing to be handed over can be determined by matching F-TEIDsor base station addresses, which can satisfy a requirement of amulti-connection scenario without adding new signaling additionally.

As another possible implementation manner, similar to that in Embodiment1, the MME can obtain the bearer needing to be handed over, withoutmatching the F-TEIDs or the base station addresses. The MME mayindicate, by using indication information, the bearer needing to behanded over. Specifically, the E-RAB modification indication messagesent by the source base station to the MME includes second indicationinformation, and the second indication information indicates the bearerneeding to be handed over. The MME determines, according to the secondindication information in the E-RAB modification indication message, thebearer needing to be handed over; the MME sends at least one bearermodification request message to the SGW, where a bearer context carriedin the at least one bearer modification request message includes onlythe context of the bearer needing to be handed over, or the at least onebearer modification request message includes first indicationinformation, where the first indication information indicates the bearerneeding to be handed over. The SGW may receive the at least one bearermodification request message sent by the mobility management entity MME,and send the End Marker message to the source base station only for thebearer needing to be handed over. A process between the source basestation and the target base station is consistent with the foregoingsolution for performing matching on the F-TEIDs or the base stationaddresses, and details are not described again.

Correspondingly, the receiving unit of the MME configured to receive abearer handover message includes:

a receiving unit, configured to receive the E-RAB modificationindication message sent by the source base station, where the E-RABmodification indication message includes the second indicationinformation, and the second indication information indicates the bearerneeding to be handed over;

the processing unit configured to determine, according to the bearerhandover message, a bearer needing to be handed over in all the bearers,so that an end marker End Marker message is sent to the source basestation only for the bearer needing to be handed over includes:

a processing unit, configured to determine, according to the secondindication information in the E-RAB modification indication message, thebearer needing to be handed over; and

the sending unit is configured to send the at least one bearermodification request message to the SGW, where the bearer contextcarried in the at least one bearer modification request message includesonly the context of the bearer needing to be handed over; or the atleast one bearer modification request message includes the firstindication information, and the first indication information indicatesthe bearer needing to be handed over.

Second indication information is added to an E-RAB modificationindication message to determine a bearer needing to be handed over, sothat an MME does not need to perform an additional matching action,thereby saving a computing resource.

Similar to Embodiment 2, different granularities may be used for thesecond indication information that is in the E-RAB modificationindication message and that the source base station notifies to the MME,which includes that: the E-RAB modification indication message includesone piece of second indication information, where the second indicationinformation indicates all the bearers in the E-RAB modificationindication message are bearers needing to be handed over; or the E-RABmodification indication message includes a plurality of pieces of secondindication information, where each bearer in the E-RAB modificationindication message corresponds to one piece of second indicationinformation, and each piece of indication information indicates whethera corresponding bearer needs to handed over. The bearer needing to behanded over can be indicated by both of the foregoing two solutions. Inthe first solution, one piece of indication information is used toindicate a plurality of bearers, which can save signaling. By using thesecond solution, whether each bearer needs to be handed over can beaccurately indicated, so that an indication is more accurate.

Same as Embodiment 1, different granularities may also be used for thefirst indication information that is in the bearer modification requestmessage and that the MME notifies to the SGW. Specifically, in thenetwork device in this embodiment, each bearer modification requestmessage of the bearer modification request message includes one piece offirst indication information, where the first indication informationindicates that all bearers in the bearer modification request arebearers needing to be handed over; or each bearer modification requestmessage of the at least one bearer modification request message includesa plurality of pieces of first indication information, where each bearerin the bearer modification request corresponds to one piece of firstindication information, and each piece of indication informationindicates whether a corresponding bearer needs to be handed over.

Embodiment 4

This embodiment of the present invention provides a bearer handovercontrol method. The method is applicable to a wireless communicationssystem, where the system includes a network side device, a source basestation, a target base station, and user equipment, and at least some ofall bearers between the user equipment and the source base station needto be handed over from the source base station to the target basestation. As shown in FIG. 9, the method includes the following steps:

901: The network side device receives a bearer handover message.

902: The network side device determines, according to the bearerhandover message, a bearer needing to be handed over in all the bearers,so that an end marker End Marker message is sent to the source basestation only for the bearer needing to be handed over.

By using the foregoing solution, for a multi-connection scenario, anetwork side device can determine a bearer needing to be handed over, sothat an end marker message is sent only for the bearer needing to behanded over, which can prevent discarding of subsequent data of a bearerthat is not to be handed over, and ensure multiple connections between aUE and base stations, thereby improving stability of a system.

A process of establishing the bearer is consistent with that inEmbodiment 1, and details are not described again.

Embodiment 5

A control method in which a network side device is an SGW is describedin this embodiment.

For detailed description of the principle of this embodiment and relatedentities, reference is made to Embodiment 2, and details are notdescribed again.

As shown in FIG. 10, in the control method provided in this embodiment,the network side device is a serving gateway SGW. The method includes:

1001: The SGW receives at least one bearer modification request messagesent by a mobility management entity MME, where bearer contexts includedin the at least one bearer modification request message correspond toall bearers.

1002: The SGW determines, according to the bearer contexts in the atleast one bearer modification request message, a bearer needing to behanded over.

1003: The SGW sends an End Marker message to a source base station onlyfor the bearer needing to be handed over.

By using the foregoing solution, for a multi-connection scenario, an SGWcan determine a bearer needing to be handed over, so that an end markermessage is sent only for the bearer needing to be handed over, which canprevent discarding of subsequent data of a bearer that is not to behanded over, and ensure multiple connections between a UE and basestations, thereby improving stability of a system.

Further, the bearer contexts included in the at least one bearermodification request message include F-TEIDs. For the specificprinciple, reference is made to Embodiment 2.

Correspondingly, in the control method in this embodiment, thedetermining, by the SGW according to the bearer contexts in the at leastone bearer modification request message, a bearer needing to be handedover includes:

matching, by the SGW, the F-TEIDs in the bearer contexts in the at leastone bearer modification request message with F-TEIDs in bearer contextsthat are currently stored by the SGW, and when an F-TEID of a bearer ischanged, determining that the bearer is a bearer needing to be handedover; or

matching, by the SGW, base station addresses in the bearer contexts inthe at least one bearer modification request message with base stationaddresses in bearer contexts that are currently stored by the SGW, andwhen a base station address of a bearer is changed, determining that thebearer is a bearer needing to be handed over.

Further, the SGW may reserve a context of a bearer that does not need tobe handed over. In this way, the SGW can keep normal communication of anoriginal bearer.

A bearer needing to be handed over can be determined by matching ofF-TEIDs or base station addresses, which can satisfy a requirement of amulti-connection scenario without adding new signaling additionally.

As another possible implementation manner, the SGW can obtain the bearerneeding to be handed over, without matching the F-TEIDs or the basestation addresses. The SGW may indicate, by using indicationinformation, the bearer needing to be handed over. For the specificprinciple, reference is made to Embodiment 2.

Correspondingly, in the control method in this embodiment, the networkside device is a serving gateway SGW, where receiving, by the networkside device, a bearer handover message includes:

receiving, by the SGW, the at least one bearer modification requestmessage sent by the mobility management entity MME, where the bearermodification request message includes first indication information, andthe first indication information indicates the bearer needing to behanded over; and

determining, by the network side device according to the bearer handovermessage, a bearer needing to be handed over in all the bearers, so thatan end marker End Marker message is sent to the source base station onlyfor the bearer needing to be handed over includes:

determining, by the SGW according to the first indication information inthe at least one bearer modification request message, the bearer needingto be handed over; and

sending, by the SGW, the End Marker message to the source base stationonly for the bearer needing to be handed over.

First indication information is added to a bearer modification requestmessage to determine a bearer needing to be handed over, so that an SGWdoes not need to perform an additional matching action, thereby saving acomputing resource.

Different granularities may be used for the first indication informationthat is in the bearer modification request message and that the MMEnotifies to the SGW, which includes that: one bearer modificationrequest message includes one piece of first indication information,where the first indication information indicates that all bearers in thebearer modification request are bearers needing to be handed over; oreach bearer modification request message of the at least one bearermodification request message includes a plurality of pieces of firstindication information, where each bearer in the bearer modificationrequest corresponds to one piece of first indication information, andeach piece of indication information indicates whether a correspondingbearer needs to be handed over. The bearer needing to be handed over canbe indicated by both of the foregoing two solutions. In the firstsolution, one piece of indication information is used to indicate aplurality of bearers, which can save signaling. By using the secondsolution, whether each bearer needs to be handed over can be accuratelyindicated, so that an indication is more accurate.

Further, the SGW may reserve a context of a bearer that does not need tobe handed over. In this way, the SGW can keep normal communication of anoriginal bearer.

Embodiment 6

A control method in which a network side device is an MME is describedin this embodiment.

For detailed description of the principle of this embodiment and relatedentities, reference is made to Embodiment 3, and details are notdescribed again.

It should be noted that in this embodiment, the MME needs to storebearer contexts of all bearers after bearer establishment.Correspondingly, an SGW does not delete a context of a bearer that isnot included in a bearer modification request message from the MME, andreserves the bearer as a bearer that does not need to be handed over.

As shown in FIG. 11, in the control method in this embodiment, thenetwork side device is a mobility management entity MME. The methodincludes:

1101: The MME receives an E-RAB modification indication message sent bya source base station, where bearer contexts included in the E-RABmodification indication message correspond to all bearers.

1102: The MME determines, according to the bearer contexts in the E-RABmodification indication message, a bearer needing to be handed over.

1103: The MME sends a bearer modification request message to an SGW,where a bearer context carried in the bearer modification requestmessage includes only a context of the bearer needing to be handed over.

Correspondingly, a control method of the SGW is:

receiving the bearer modification request message, where the bearermodification request message indicates the bearer needing to be handedover and the context of the bearer needing to be handed over;

generating an End Marker message according to the bearer modificationrequest message for the bearer needing to be handed over; and

sending the End Marker message for the bearer needing to be handed over.

Further, the control method of the SGW further includes: reserving, bythe SGW, a context of a bearer that does not need to be handed over.

By using the foregoing solution, for a multi-connection scenario, an MMEcan determine a bearer needing to be handed over, so that an SGW cansend an end marker message only for the bearer needing to be handedover, which can prevent discarding of subsequent data of a bearer thatis not to be handed over, and ensure multiple connections between a UEand base stations, thereby improving stability of a system.

Further, the bearer contexts included in the E-RAB modificationindication message include F-TEIDs. For the specific principle,reference is made to Embodiment 3.

Correspondingly, in the control method in this embodiment, thedetermining, by the MME according to the bearer contexts in the E-RABmodification indication message, a bearer needing to be handed overincludes:

matching, by the MME, the F-TEIDs in the bearer contexts of all thebearers in the E-RAB modification indication message with F-TEIDs ofcurrently stored bearer contexts, and when an F-TEID of a bearer ischanged, determining that the bearer is a bearer needing to be handedover; or

matching, by the MME, target base station addresses in the bearercontexts of all the bearers in the E-RAB modification indication messagewith base station addresses in bearer contexts that are currently storedby the MME, and when a base station address of a bearer is changed,determining that the bearer is a bearer needing to be handed over.

A bearer needing to be handed over can be determined by matching ofF-TEIDs or base station addresses, which can satisfy a requirement of amulti-connection scenario without adding new signaling additionally.

As another possible implementation manner, similar to that in Embodiment1, the MME can obtain the bearer needing to be handed over, withoutmatching the F-TEIDs or the base station addresses. The MME mayindicate, by using indication information, the bearer needing to behanded over. For the specific principle, reference is made to Embodiment3.

Correspondingly, in the control method in this embodiment, the networkside device is a mobility management entity MME, where

receiving, by the network side device, a bearer handover messageincludes: receiving, by the MME, the E-RAB modification indicationmessage sent by the source base station, where the E-RAB modificationindication message includes second indication information, and thesecond indication information indicates the bearer needing to be handedover; and

determining, by the network side device according to the bearer handovermessage, a bearer needing to be handed over in all bearers, so that anend marker End Marker message is sent to the source base station onlyfor the bearer needing to be handed over includes:

determining, by the MME according to the second indication informationin the E-RAB modification indication message, the bearer needing to behanded over; and

sending, by the MME, at least one bearer modification request message tothe SGW, where a bearer context carried in the at least one bearermodification request message includes only the context of the bearerneeding to be handed over; or the at least one bearer modificationrequest message includes first indication information, and the firstindication information indicates the bearer needing to be handed over.

Second indication information is added to an E-RAB modificationindication message to determine a bearer needing to be handed over, sothat an MME does not need to perform an additional matching action,thereby saving a computing resource.

Similar to Embodiment 3, different granularities may be used for thesecond indication information that is in the E-RAB modificationindication message and that the source base station notifies to the MME,which includes that: the E-RAB modification indication message includesone piece of second indication information, where the indicationinformation indicates all the bearers in the E-RAB modificationindication message are bearers needing to be handed over; or the E-RABmodification indication message includes a plurality of pieces of secondindication information, where each bearer in the E-RAB modificationindication message corresponds to one piece of second indicationinformation, and each piece of indication information indicates whethera corresponding bearer needs to handed over. The bearer needing to behanded over can be indicated by both of the foregoing two solutions. Inthe first solution, one piece of indication information is used toindicate a plurality of bearers, which can save signaling. By using thesecond solution, whether each bearer needs to be handed over can beaccurately indicated, so that an indication is more accurate.

Same as Embodiment 1, different granularities may also be used for thefirst indication information that is in the bearer modification requestmessage and that the MME notifies to the SGW. Specifically, in thecontrol method in this embodiment, each bearer modification requestmessage of the bearer modification request message includes one piece offirst indication information, where the first indication informationindicates that all bearers in the bearer modification request arebearers needing to be handed over; or each bearer modification requestmessage of the at least one bearer modification request message includesa plurality of pieces of first indication information, where each bearerin the bearer modification request corresponds to one piece of firstindication information, and each piece of first indication informationindicates whether a corresponding bearer needs to be handed over.

Embodiment 7

The foregoing embodiments mainly describe improvement of an SGW or anMME. A technical solution of a source base station is described below.The solution can also implement bearer control in a multi-connectionscenario.

As described in Embodiment 2, a UE keeps in communication with a sourcebase station, and the source base station prepares, according toconditions of bearers, to hand over some of the bearers to a target basestation. Specifically, the source base station may determine, by using aparameter such as Qos of the UE or the source base station or a loadcondition between the UE and the source base station, a bearer needingto be handed over. In this embodiment, bearer contexts obtained by thesource base station, an MME, and an SGW correspond to all bearers.Correspondingly, End Marker messages sent by the SGW correspond to allthe bearers, that is, a bearer needing to be handed over is included,and a bearer that does not need to be handed over is also included. Inthis embodiment, the source base station may discard, according to thebearer needing to be handed over and determined by the source basestation, an END marker message corresponding to the bearer that does notneed to be handed over. In this way, the bearer that does not need to behanded over is reserved, and the UE continues to communicate on a bearerof the source base station. Correspondingly, the source base stationforwards an End Marker message to the target base station. The forwardedEnd Marker message corresponds to the bearer needing to be handed over.After receiving the message, the target base station may confirm thatthe source base station has completed sending the bearer needing to behanded over, and start communication between the target base station andthe corresponding UE and network side device.

Correspondingly, this embodiment provides a base station, configured fora bearer handover. The base station belongs to a wireless communicationssystem, where the system includes an SGW and a target base station, andat least some of all bearers between user equipment and the base stationneeds to be handed over from the base station to the target basestation, and the base station includes:

a receiving unit, configured to receive End Marker messages sent by theSGW, where the End Marker messages are End Marker messages correspondingto all bearers; and

a processing unit, configured to determine a bearer needing to be handedover, and

further configured to discard, according to the determined bearerneeding to be handed over, an End Marker message corresponding to abearer that does not need to be handed over.

Further, the base station may further include a sending unit, configuredto forward, to the target base station, an End Marker messagecorresponding to the bearer needing to be handed over.

Optionally, a context of the bearer needing to be handed over may bestored in a memory of the base station.

Specifically, the processing unit of the base station is configured tomatch a bearer corresponding to an End Marker message with thedetermined bearer needing to be handed over, and when the two areinconsistent, discard the End Marker message corresponding to thebearer, or when the two are consistent, forward the End Marker messagecorresponding to the bearer to the target base station. In this way, thebase station reserves the bearer that does not need to be handed over,so that a communication break is not caused.

In addition, this embodiment provides a base station, configured for abearer handover. The base station belongs to a wireless communicationssystem, where the system includes an SGW and a target base station, andat least some of all bearers between user equipment and the base stationneeds to be handed over from the base station to the target basestation, and the base station includes:

a receiver, configured to receive End Marker messages sent by the SGW,where the End Marker messages are End Marker messages corresponding toall bearers; and

a processor, configured to determine a bearer needing to be handed over,and

further configured to discard, according to the determined bearerneeding to be handed over, an End Marker message corresponding to abearer that does not need to be handed over.

Further, the base station may further include a transmitter, configuredto forward, to the target base station, an End Marker messagecorresponding to the bearer needing to be handed over.

Optionally, a context of the bearer needing to be handed over may bestored in a memory of the base station.

Specifically, the processing unit of the base station is configured tomatch a bearer corresponding to an End Marker message with thedetermined bearer needing to be handed over, and when the two areinconsistent, discard the End Marker message corresponding to thebearer, or when the two are consistent, forward the End Marker messagecorresponding to the bearer to the target base station. In this way, thebase station reserves the bearer that does not need to be handed over,so that a communication break is not caused.

This embodiment provides a control method used by a base station. Themethod is applicable to a wireless communications system, where thesystem includes an SGW, a source base station, and a target basestation, and at least some of all bearers between user equipment and thesource base station need to be handed over from the source base stationto the target base station, and the method includes the following steps:

receiving, by the source base station, End Marker messages, where theEnd Marker messages are End Marker messages corresponding to all thebearers;

determining, by the source base station, a bearer needing to be handedover; and

discarding, by the source base station according to the determinedbearer needing to be handed over, an End Marker message corresponding toa bearer that does not need to be handed over.

Further, an End Marker message corresponding to the bearer needing to behanded over may be forwarded to the target base station.

Specifically, the source base station matches a bearer corresponding toan End Marker message with the determined bearer needing to be handedover, and when the two are inconsistent, discards the End Marker messagecorresponding to the bearer, or when the two are consistent, forwardsthe End Marker message corresponding to the bearer to the target basestation. In this way, the source base station reserves the bearer thatdoes not need to be handed over, so that a communication break is notcaused.

By using the foregoing solution, for a multi-connection scenario, a basestation can determine a bearer needing to be handed over, and discard anend marker message corresponding to a bearer that does not need to behanded over, which can prevent discarding of subsequent data of a bearerthat is not to be handed over, and ensure multiple connections between aUE and base stations, thereby improving stability of a system.

Embodiment 8

This embodiment is also an improved solution of a source base station.The solution can also implement bearer control in a multi-connectionscenario.

As described in Embodiment 2, a UE keeps in communication with a sourcebase station, and the source base station prepares, according toconditions of bearers, to hand over some of the bearers to a target basestation. Specifically, the source base station may determine, by using aparameter such as Qos of the UE or the source base station or a loadcondition between the UE and the source base station, a bearer needingto be handed over. In this embodiment, the source base station sendsonly an E-RAB modification indication message corresponding to thebearer needing to be handed over to an MME. Correspondingly, the MMEsends a bearer modification request to an SGW according to the E-RABmodification indication message, where the bearer modification requestcorresponds only to the bearer needing to be handed over; the SGW sendsan End Marker message to the source base station according to the bearermodification request, where the End Marker message corresponds only tothe bearer needing to be handed over. It should be noted that, the SGWand/or the MME needs to reserve a context of a bearer that does not needto be handed over. The End Marker message received by the source basestation corresponds only to the bearer needing to be handed over, wherethe bearer that does not need to be handed over is not included.Correspondingly, the source base station reserves the bearer that doesnot need to be handed over, and stops a subsequent packet of the bearerneeding to be handed over. The source base station transfers, to thetarget base station, the bearer needing to be handed over. The sourcebase station may also forward the received End Marker message to thetarget base station; after receiving the message, the target basestation may confirm that the source base station has completed sendingthe bearer needing to be handed over, and start communication betweenthe target base station and the corresponding UE and network sidedevice.

Correspondingly, this embodiment provides a base station, configured fora bearer handover. The base station belongs to a wireless communicationssystem, where the system includes an SGW, an MME, and a target basestation, and at least some of all bearers between user equipment and thebase station needs to be handed over from the source base station to thetarget base station, and the base station includes:

a receiving unit, configured to determine a bearer needing to be handedover, and

a sending unit, configured to send an E-RAB modification indicationmessage to the MME, where the E-RAB modification indication messageincludes only a context of the bearer needing to be handed over, where

the receiving unit is further configured to receive an End Markermessage sent by the SGW, where the End Marker message corresponds onlyto the bearer needing to be handed over.

Further, the sending unit of the base station is further configured toforward, to the target base station, the End Marker messagecorresponding to the bearer needing to be handed over.

In addition, this embodiment provides a base station, configured for abearer handover. The base station belongs to a wireless communicationssystem, where the system includes an SGW, an MME, and a target basestation, and at least some of all bearers between user equipment and thebase station needs to be handed over from the source base station to thetarget base station, and the base station includes:

a receiver, configured to determine a bearer needing to be handed over,and

a transmitter, configured to send an E-RAB modification indicationmessage to the MME, where the E-RAB modification indication messageincludes only a context of the bearer needing to be handed over, where

the receiver is further configured to receive an End Marker message sentby the SGW, where the End Marker message corresponds only to the bearerneeding to be handed over.

Further, the transmitter of the base station is further configured toforward, to the target base station, the End Marker messagecorresponding to the bearer needing to be handed over.

This embodiment provides a control method used by a base station. Themethod is applicable to a wireless communications system, where thesystem includes an SGW, an MME, a source base station, and a target basestation, and at least some of all bearers between user equipment and thesource base station need to be handed over from the source base stationto the target base station, and the method includes the following steps:

determining, by the source base station, a bearer needing to be handedover.

sending, by the source base station, an E-RAB modification indicationmessage to the MME, where the E-RAB modification indication messageincludes only a context of the bearer needing to be handed over; and

receiving, by the source base station, an End Marker message sent by theSGW, where the End Marker message corresponds only to the bearer needingto be handed over. Further, the End Marker message corresponding to thebearer needing to be handed over may be forwarded to the target basestation.

Correspondingly, this embodiment provides a communications system,configured for a bearer handover. The system includes an SGW, an MME, asource base station, and a target base station, where at least some ofall bearers between user equipment and the source base station need tobe handed over from the source base station to the target base station,and the source base station is the base station in this embodiment.

Because an End Marker message is generated only for a bearer needing tobe handed over and no corresponding End Marker message is generated fora bearer that does not need to be handed over, the bearer that does notneed to be handed over does not cause a communication break. By usingthe foregoing solution, for a multi-connection scenario, a source basestation can prevent discarding of subsequent data of a bearer that isnot to be handed over, and ensure multiple connections between a UE andbase stations, thereby improving stability of a system.

Embodiment 9

This embodiment of the present invention provides a network side device,configured to control a bearer handover. The network side device belongsto a wireless communications system, where the system further includes asource base station and a target base station, and at least some of allbearers between user equipment and the source base station need to behanded over from the source base station to the target base station. Asshown in FIG. 12, the network side device 1200 includes:

a receiver 1203, configured to receive a bearer handover message; and

a processor 1201, configured to determine, according to the bearerhandover message, a bearer needing to be handed over in all the bearers,so that an end marker End Marker message is sent to the source basestation only for the bearer needing to be handed over.

In this embodiment, the processor 1201 can complete all functions of theprocessing unit in Embodiment 1 or perform same steps; the receiver 1203can complete all functions of the receiving unit in Embodiment 1 orperform same steps. A connection relationship between the processor andthe receiver is consistent with a connection relationship between theprocessing unit and the receiving unit in Embodiment 1. This embodimentis an apparatus embodiment similar to Embodiment 1, and can implement aneffect similar to that of Embodiment 1, and details are not describedagain.

By using the foregoing solution, for a multi-connection scenario, anetwork side device can determine a bearer needing to be handed over, sothat an end marker message is sent only for the bearer needing to behanded over, which can prevent discarding of subsequent data of a bearerthat is not to be handed over, and ensure multiple connections between aUE and base stations, thereby improving stability of a system.

Embodiment 10

A technical solution in which a network side device is an SGW isdescribed in this embodiment.

As shown in FIG. 13, the SGW 1300 may include: a receiver 1303,configured to receive at least one bearer modification request messagesent by a mobility management entity MME, where bearer contexts includedin the at least one bearer modification request message correspond toall bearers;

a processor 1301, configured to determine, according to the bearercontexts in the at least one bearer modification request message, abearer needing to be handed over; and

a transmitter 1302, configured to send an End Marker message to a sourcebase station only for the bearer needing to be handed over.

In this embodiment, the processor 1301 can complete all functions of theprocessing unit in Embodiment 2 or perform same steps; the receiver 1303can complete all functions of the receiving unit in Embodiment 2 orperform same steps; the transmitter 1302 can complete all functions ofthe sending unit in Embodiment 2 or perform same steps. A connectionrelationship between the processor, the receiver, and the transmitter isconsistent with a connection relationship between the processing unit,the receiving unit, and the sending unit in Embodiment 2. Thisembodiment is an apparatus embodiment similar to Embodiment 2, and canimplement an effect similar to that of Embodiment 2, and details are notdescribed again.

By using the foregoing solution, for a multi-connection scenario, an SGWcan determine a bearer needing to be handed over, so that the SGW sendsan end marker message only for the bearer needing to be handed over,which can prevent discarding of subsequent data of a bearer that is notto be handed over, and ensure multiple connections between a UE and basestations, thereby improving stability of a system.

Embodiment 11

A technical solution in which a network side device is an MME isdescribed in this embodiment.

As shown in FIG. 14, the MME 1400 may include:

a receiver 1403, configured to receive an E-RAB modification indicationmessage sent by a source base station, where bearer contexts included inthe E-RAB modification indication message correspond to all bearers; and

a processor 1401, configured to determine, according to the bearercontexts in the E-RAB modification indication message, a bearer needingto be handed over; and

a transmitter 1402, configured to send a bearer modification requestmessage to an SGW, where a bearer context carried in the bearermodification request message includes only a bearer context of thebearer needing to be handed over.

In this embodiment, the processor 1401 can complete all functions of theprocessing unit in Embodiment 3 or perform same steps; the receiver 1403can complete all functions of the receiving unit in Embodiment 3 orperform same steps; the transmitter 1402 can complete all functions ofthe sending unit in Embodiment 3 or perform same steps. A connectionrelationship between the processor, the receiver, and the transmitter isconsistent with a connection relationship between the processing unit,the receiving unit, and the sending unit in Embodiment 3. Thisembodiment is an apparatus embodiment similar to Embodiment 3, and canimplement an effect similar to that of Embodiment 3, and details are notdescribed again.

By using the foregoing solution, for a multi-connection scenario, an MMEmay determine a bearer needing to be handed over, so that an SGW maysend an end marker message only for the bearer needing to be handedover, which can prevent discarding of subsequent data of a bearer thatis not to be handed over, and ensure multiple connections between a UEand base stations, thereby improving stability of a system.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, method steps and units may be implemented by electronichardware, computer software, or a combination thereof. To clearlydescribe the interchangeability between the hardware and the software,the foregoing has generally described steps and compositions of eachembodiment according to functions. Whether the functions are performedby hardware or software depends on particular applications and designconstraint conditions of the technical solutions. A person of ordinaryskill in the art may use different methods to implement the describedfunctions for each particular application, but it should not beconsidered that the implementation goes beyond the scope of the presentinvention. When the present invention is implemented by software, theforegoing functions may be stored in a computer-readable medium ortransmitted as one or more instructions or code in the computer-readablemedium. The computer-readable medium includes a computer storage mediumand a communications medium, where the communications medium includesany medium that enables a computer program to be transmitted from oneplace to another. The storage medium may be any available mediumaccessible to a computer. The following provides an example but does notimpose a limitation: The computer-readable medium may include a RAM, aROM, an EEPROM, a CD-ROM, or another optical disc storage or diskstorage medium, or another magnetic storage device, or any other mediumthat can carry or store expected program code in a form of aninstruction or a data structure and can be accessed by a computer. Inaddition, any connection may be appropriately defined as acomputer-readable medium. For example, if software is transmitted from awebsite, a server or another remote source by using a coaxial cable, anoptical fiber/cable, a twisted pair, a digital subscriber line (DSL) orwireless technologies such as infrared ray, radio and microwave, thecoaxial cable, optical fiber/cable, twisted pair, DSL or wirelesstechnologies such as infrared ray, radio and microwave are included infixation of a medium to which they belong. For example, a disk (Disk)and disc (disc) used by the present invention includes a compact discCD, a laser disc, an optical disc, a digital versatile disc (DVD), afloppy disk and a Blu-ray disc, where the disk generally copies data bya magnetic means, and the disc copies data optically by a laser means.The foregoing combination should also be included in the protectionscope of the computer-readable medium.

The present invention is described in detail with reference to theaccompany drawings and in combination with the exemplary embodiments,but the present invention is not limited thereto. Various equivalentmodifications or replacements can be made to the embodiments of thepresent invention by a person of ordinary skill in the art withoutdeparting from the essence of the present invention, and themodifications or replacements shall fall within the scope of the presentinvention.

What is claimed is:
 1. A network side device, configured to control abearer handover, wherein the network side device belongs to a wirelesscommunications system, wherein the system further comprises a sourcebase station and a target base station, and at least some of all bearersbetween user equipment and the source base station need to be handedover from the source base station to the target base station, and thenetwork side device comprises: a receiver, configured to receive abearer handover message; a processor, configured to determine, accordingto the bearer handover message, a bearer needing to be handed over inall the bearers; and a transmitter, configured to send an end markermessage to the source base station only for the bearer needing to behanded over.
 2. The network side device according to claim 1, whereinthe network side device is a serving gateway SGW, wherein the receiveris configured to receive at least one bearer modification requestmessage sent by a mobility management entity (MME), wherein bearercontexts comprised in the at least one bearer modification requestmessage correspond to all the bearers; the processor is configured todetermine, according to the bearer contexts in the at least one bearermodification request message, the bearer needing to be handed over; andthe transmitter is configured to send the End Marker message to thesource base station only for the bearer needing to be handed over. 3.The network side device according to claim 2, wherein the processor isconfigured to match fully qualified tunnel endpoint identifiers(F-TEIDs) in the bearer contexts in the at least one bearer modificationrequest message with F-TEIDs in bearer contexts that are currentlystored by the SGW, and when an F-TEID of a bearer is changed, determinethat the bearer is a bearer needing to be handed over.
 4. The networkside device according to claim 1, wherein the network side device is aserving gateway SGW, wherein the receiver is configured to receive atleast one bearer modification request message sent by a mobilitymanagement entity MME, wherein the at least one bearer modificationrequest message comprises first indication information, and the firstindication information indicates the bearer needing to be handed over;the processor is configured to determine, according to the firstindication information in the at least one bearer modification requestmessage, the bearer needing to be handed over; and the transmitter isconfigured to send the End Marker message to the source base stationonly for the bearer needing to be handed over.
 5. The network sidedevice according to claim 4, wherein each bearer modification requestmessage of the at least one bearer modification request messagecomprises one piece of first indication information, wherein the firstindication information indicates that all bearers in the at least onebearer modification request message are bearers needing to be handedover; or each bearer modification request message of the at least onebearer modification request message comprises a plurality of pieces offirst indication information, wherein each bearer in the bearermodification request corresponds to one piece of first indicationinformation, and each piece of the first indication informationindicates whether a corresponding bearer needs to be handed over.
 6. Thenetwork side device according to claim 2, wherein the processing unit ofthe SGW is further configured to reserve a context of a bearer that doesnot need to be handed over.
 7. A bearer handover control method, whereinthe method is applicable to a wireless communications system, whereinthe system comprises a network side device, a source base station, and atarget base station, and at least some of all bearers between userequipment and the source base station need to be handed over from thesource base station to the target base station, and the method comprisesfollowing steps: receiving, by the network side device, a bearerhandover message; determining, by the network side device according tothe bearer handover message, a bearer needing to be handed over in allthe bearers; and sending an end marker message to the source basestation only for the bearer needing to be handed over.
 8. The controlmethod according to claim 7, wherein the network side device is aserving gateway SGW, wherein the receiving, by the network side device,a bearer handover message comprises: receiving, by the SGW, at least onebearer modification request message sent by a mobility management entityMME, wherein bearer contexts comprised in the at least one bearermodification request message correspond to all the bearers; thedetermining, by the network side device according to the bearer handovermessage, a bearer needing to be handed over in all the bearers,comprises: determining, by the SGW according to the bearer contexts inthe at least one bearer modification request message, the bearer needingto be handed over; and the sending, by the network side device, the endmarker message to the source base station comprises: sending, by theSGW, the End Marker message to the source base station only for thebearer needing to be handed over.
 9. The control method according toclaim 8, wherein the determining, by the SGW according to the bearercontexts in the at least one bearer modification request message, thebearer needing to be handed over comprises: matching, by the SGW, fullyqualified tunnel endpoint identifiers (F-TEIDs) in the bearer contextsin the at least one bearer modification request message with F-TEIDs inbearer contexts that are currently stored by the SGW, and when an F-TEIDof a bearer is changed, determining that the bearer is a bearer needingto be handed over.
 10. The control method according to claim 7, whereinthe network side device is a serving gateway SGW, wherein the receiving,by the network side device, a bearer handover message comprises:receiving, by the SGW, at least one bearer modification request messagesent by a mobility management entity MME, wherein the at least onebearer modification request message comprises first indicationinformation, and the first indication information indicates the bearerneeding to be handed over; the determining, by the network side deviceaccording to the bearer handover message, a bearer needing to be handedover in all the bearers, comprises: determining, by the SGW according tothe first indication information in the at least one bearer modificationrequest message, the bearer needing to be handed over; and the sending,by the network side device, the end marker message to the source basestation comprises: sending, by the SGW, the End Marker message to thesource base station only for the bearer needing to be handed over. 11.The control method according to claim 10, wherein each bearermodification request message of the at least one bearer modificationrequest message comprises one piece of first indication information,wherein the first indication information indicates that all bearers inthe at least one bearer modification request message are bearers needingto be handed over; or each bearer modification request message of the atleast one bearer modification request message comprises a plurality ofpieces of first indication information, wherein each bearer in thebearer modification request corresponds to one piece of first indicationinformation, and each piece of the first indication informationindicates whether a corresponding bearer needs to be handed over. 12.The control method according to claim 8, further comprising: reserving,by the SGW, a context of a bearer that does not need to be handed over.13. A computer program product, comprising computer program code, which,when executed by a computer unit, will cause the computer unit toperform the steps: receiving a bearer handover message; determiningaccording to the bearer handover message, a bearer needing to be handedover in all the bearers; and sending an end marker message to the sourcebase station only for the bearer needing to be handed over.